Thick Film Ceramic Resistors

Thick Film Ceramic Resistors are high-reliability, precision electronic components primarily used to control the flow of current in circuits, providing functions such as circuit regulation, power distribution, and protection, manufactured using thick film resistor technology combined with ceramic substrates, where resistive and conductive materials are printed onto alumina or aluminum nitride substrates, sintered at high temperatures, followed by coating of an insulating layer and laser trimming for improved resistance accuracy, resulting in stable, durable, and customizable resistor elements formed on the ceramic substrate.

Thick Film Ceramic Resistors are known for their high stability, reliability, and versatility in electronics. With resistive elements printed on a ceramic substrate, they offer excellent thermal conductivity and mechanical strength. These resistors can withstand high temperatures and harsh environments, making them ideal for industrial, automotive, and consumer electronics. They provide precise resistance values, good tolerance, and power handling, ensuring consistent performance over time, while their compact design and cost-effective production make them suitable for high-volume applications.

Thick Film Ceramic Resistors are used in various electronic devices, including power supplies, amplifiers, and control circuits. Their durability makes them ideal for automotive and industrial equipment, as well as consumer electronics like televisions, computers, and communication devices. Their ability to handle different power ratings and tolerance levels makes them versatile across multiple sectors, contributing to the longevity and reliability of many products.

Main Features of Thick Film Ceramic Resistors :

1,Circuit Miniaturization: Thick Film Resistors has the advantages of circuit miniaturization together with increased reliability, low weight and Low cost. By using a Thick Film circuit instead of a PCB many benefits are gained – reduced component count, lower assembly costs, and quicker assembly/test times along with increased reliability.

2, Geometries and Sizes: Thick Film Ceramic Resistors can be customed and manufactured in many geometries and sizes, from fractional watts to kilowatts, with different resistor artworks, resistance values, surface mount, or special footprints can be met easily.

3, Good Power Handling Capacity: Thick film resistors can dissipate relatively high levels of power without significant degradation in performance. This makes them suitable for applications with high power loads.

4, Resistance Value and Dimension can be Customizable: Thick Film Ceramic Resistor achieves this with the ability to produce integrated resistors of small size, planar 2D construction, with high reliability, high power density and high stability. This means that resistors can be made as small as 1mm square with no significant thickness. Another added bonus is that the resistors are not limited to preferred values. Almost any value is possible from less than 10 ohm to greater than 100 M ohm, with tolerances as tight as 1% depending on value. The temperature stability is also very good with 100ppm/deg C being typical.

5, Typical Applications: Thick Film Ceramic Resistors are ideal for a wide range of requirements in equipment,makes it highly applicable to Commercial, Industrial, Scientific and Military applications, such as radar, motor drives, broadcast transmitters, RF amplifiers, semiconductor process, power conditioning, xray, lasers, medical defibrillators, and energy research.

6, Non-Inductive,Thermal Stability and High Reliability: As its chemically inert and thermally stable, the resistors are inherently non-inductive because of their bulk ceramic construction, Thick Film Ceramic Resistor allows energy and power to be uniformly distributed through the entire ceramic resistor,The bulk ceramic material also allows simple-efficient resistor designs that enable the designer to minimize the resistor package size while providing the required performance and reliability.

7, Low Temperature Coefficient: Thick film cermaic resistors exhibit a low temperature coefficient of resistance (TCR), meaning their resistance remains relatively stable across a wide range of temperatures. This characteristic helps maintain circuit performance in varying temperature environments.

8, Assembly Diversity: Based on Thick Film Ceramic Resistor Technologies, we can put resistor, electric capacity, conductor, semi-conductor, and interchangable conductor on ceramic board, after manufacturing steps of printing and high temperature sintering. The resistors can be laser trimming with high tolerance condition, So we can make all the resistors with the same value, or different value for different resistor on the same substrate.

Please refer to Thick Film Technology for more informations.

Product Types of Thick Film Ceramic Resistors :

1, High Value Ceramic Resistors

2, High Voltage Ceramic Resistors

3, Humidity Sensitive Ceramic Resistors

4, Ceramic Non-Inductive Resistors

5, High Energy Ceramic Resistors

6, Radio Frequency Power Resistors

7, High Power Ceramic Resistors

8, Ceramic Planar Resistors

9, Ceramic Tubular Resistors

10, Thick Film Resistor Networks

11, High Voltage Divider Resistors

12, Ceramic Variable Resistors

Benefits of Thick Film Ceramic Resistors :

Thick Film Ceramic Resistors offer several benefits that make them a preferred choice in various electronic applications. These benefits include:

1, High Precision: Thick film ceramic resistors are known for their precise resistance values and tolerance levels. This level of accuracy ensures optimal performance and reliability in electronic applications.

2, Stability and Reliability: With superior stability against changes in temperature and humidity, these thick film ceramic resistors offer reliable operation even in demanding environments. The thick film technology used in their manufacturing process ensures consistent performance over time.

3, Compact Design: These thick film resistors feature a compact and space-saving design, making them suitable for modern electronic devices with limited space availability. Their small size facilitates easy integration and allows for efficient circuit board layout.

4, Wide Range of Resistance Values: Thick film ceramic resistors are available in a broad range of resistance values, allowing designers and engineers to select the most suitable component for their specific circuit requirements.

5, Power Handling Capability: Our thick film ceramic resistors can handle significant power dissipation, making them ideal for high-power applications. They can withstand high surge currents and maintain stable resistance under various load conditions.

6, Power Handling Capability: Thick film ceramic resistors can handle high power loads without compromising performance or reliability. They have good thermal conductivity, which helps dissipate heat efficiently.

7, RoHS Compliant: Our thick film resistors comply with the Restriction of Hazardous Substances (RoHS) directive, ensuring their safety and environmental friendliness.

8, Excellent Thermal Properties: Thick film ceramic resistors possess exceptional thermal conductivity, enabling efficient heat dissipation. This trait ensures proper functioning, even in applications that generate high levels of heat.

9, Cost-Effective: Thick film ceramic resistors are generally more cost-effective compared to other types of resistors. Their manufacturing process, such as screen printing, allows for efficient mass production, resulting in lower production costs. This cost-effectiveness makes thick film resistors an economical choice for many electronic devices and systems.

The high power handling capacity, stability, customization options, and cost-effectiveness of thick film resistors make them a reliable and versatile choice for a wide range of electronic applications.

Typical Applications of Thick Film Ceramic Resistors :

1, Consumer Electronics: Thick film ceramic resistors are widely used in consumer electronics such as televisions, audio systems, mobile phones, and gaming consoles. They are employed in circuits for volume control, signal conditioning, and voltage regulation.

2, Industrial Electronics: Thick film ceramic resistors are utilized in industrial automation systems, power supplies, motor control circuits, and instrumentation equipment. They help regulate current flow, provide voltage division, and offer stability in harsh industrial environments.

3, Automotive Electronics: Thick film ceramic resistors are extensively used in automotive applications, including engine control units (ECUs), lighting systems, infotainment systems, and sensors. They provide accurate resistance values and can withstand the demanding conditions of the automotive environment.

4, Medical Devices: Thick film ceramic resistors are employed in various medical devices, such as patient monitoring systems, diagnostic equipment, and imaging devices. They contribute to precision measurement, signal processing, and control functions.

5, Telecommunications: Thick film ceramic resistors play a crucial role in telecommunications equipment, including routers, switches, base stations, and network infrastructure. They are used in signal conditioning, impedance matching, and filtering circuits.

6, Power Electronics: Thick film resistors are utilized in power electronics applications, such as power supplies, inverters, converters, and motor drives. They help control current levels, provide voltage division, and dissipate power efficiently.

7, Aerospace and Defense: Thick film ceramic resistors are utilized in aerospace and defense applications, including avionics systems, radar equipment, communication systems, and missile guidance systems. They offer stability, reliability, and performance under extreme conditions.

8, Renewable Energy Systems: Thick film ceramic resistors are employed in renewable energy systems, such as solar inverters, wind turbine control circuits, and energy storage systems. They assist in power conversion, voltage regulation, and fault protection.

These are just a few examples of the wide range of applications where thick film resistors are utilized. Their stability, power handling capacity, resistance to environmental factors, and cost-effectiveness make them suitable for numerous electronic devices and circuits in various industries.

Design Guideline of Thick Film Ceramic Resistors :

Guidelines for Thick Film Ceramic Resistors include the following considerations:

1, Material Selection: Choose the appropriate resistor material based on the required resistance, temperature coefficient of resistance (TCR), and stability over time and temperature.

2, Substrate Selection: Select a suitable substrate material with good thermal conductivity, coefficient of thermal expansion (CTE) matching the components it will be interfacing with, and good adhesion to the resistor material.

3, Resistance Value: Determine the desired resistance value and tolerance, and design the resistor dimensions accordingly.

4, Dimensions and Geometry: Design the physical dimensions and geometries of the resistor such as length, width, and thickness to achieve the desired resistance value and power rating.

5, Power Rating: Calculate the power handling capability of the resistor and ensure that the chosen dimensions and materials can withstand the expected power dissipation.

6, Termination Design: Determine the termination style and material to ensure proper electrical contact and mechanical stability.

7, Temperature Coefficient: Consider the temperature coefficient of resistance (TCR) and its impact on circuit performance over the expected operating temperature range.

8, Stability and Reliability: Ensure that the resistor design provides long-term stability and reliability under operating conditions including temperature cycling, humidity, and mechanical stress.

9, Environmental Considerations: Consider environmental factors such as moisture resistance, chemical resistance, and resistance to soldering processes if applicable.

10, Testing and Quality Control: Develop testing procedures to verify the performance of the designed resistors and implement quality control measures to ensure consistency and reliability.

By considering these guidelines, engineers can design Thick Film Ceramic Resistors that meet the requirements of specific applications and provide reliable performance in electronic circuits.

1, Basic Parameters Capabilities :

2, Engineering Specifications :

1, Rated power: 2.5w-20w.
2, Resistance range: 10 Ω ~ 10G Ω.
3, Allowable deviation: ± 1% ～ ± 10%.
4,Temperature coefficient: minimum ± 50ppm (25 ℃ ~ 105 ℃).
5, Insulation withstand voltage: > 1000VDC.
6, Insulation resistance: ≥ 10g Ω.
7, Working temperature range: - 55 ℃ ~ + 225 ℃.
8, Maximum working voltage: 48kvdc.
9, Inductance: non inductive.
10, Connectors: tinned iron cap.
11, Resistance installation: Welding.
12, Overload: 5p value does not exceed 1.5umax5s, Δ R≤±0.2%R.
13, Service life: rated power 1000h, Δ R≤±0.5%R.
14, Steady state damp heat: mil-std-202, method 103, condition D, Δ R≤±0.4%R.
15, Thermal shock: mil-std-202, method 107, condition C, Δ R≤±0.2%R.

1, Ceramic substrate can be 96% or 98% Alumina (Al2O3) or Beryllium Oxide (BeO), thickness range: 0.25mm, 0.38mm, 0.50mm, 0.635mm , 0.76mm, 1.0mm, 1.2mm, 1.6mm or 2.0mm, or can be customizable too.
2, Printing Accuracy: ±2 mil.
3, Printing Size: 210mm*297mm (Max).
4, Line width, Line gape:6/ 6mil (Min).
5, Resistor value: 10Ω~1000MΩ.
6, Precision resistor: ±0.2%, ±0.5%, ±1%，±2%，±5%，±0.5%.
7, Laser trim: Functional trimming.
8, Print not only at Ceramic but also at Stainless, FR4, Flexiable PI.
9, Die assembly and AI wedge bonding.
10, Lead out: SIP and DIP, Pitch2.54mm and1.78mm.
11, Covering with insulatingcoating and molding.
12, Having ability to work in gasoline, High temperature, high voltage and high humidity working environment.

Differences Between Thin Film and Thick Film Ceramic Resistors :

Thin and Thick Film Ceramic Resistors are the most common types in the market. They are characterized by a resistive layer on a ceramic base. Although their appearance might be very similar, their properties and manufacturing processes are very different as following :

1, Temperature Coefficient:
Thin film resistors generally exhibit a lower temperature coefficient of resistance (TCR) compared to thick film resistors. This means that the resistance of thin film resistors changes less with temperature variations, making them more suitable for applications requiring stability over a wide temperature range.

2, Thickness of Resistive Film:
The naming originates from the different layer thicknesses. Thin film has a thickness in the order of 0.1 um (micrometer) or smaller, while thick film ceramic resistor is hundreds times thicker.

3, Manufacturing Process:
The main difference lies in the manufacturing process. Thin film resistors are typically fabricated by printing a thin layer of resistive material, such as nickel-chrome or tantalum nitride, onto a ceramic substrate using vacuum deposition techniques. In contrast, thick film resistors are made by screen printing a thick layer of resistive paste, usually a mixture of glass and metal oxides, onto a ceramic substrate and then firing it at high temperatures to achieve the desired properties.

4, Frequency Response:
Thin film resistors tend to have better high-frequency characteristics compared to thick film resistors. This makes them more suitable for applications involving radio frequency (RF) signals or high-speed digital circuits.

5, Resistance Value and Tolerance:
Thin film resistors offer a higher level of precision and accuracy compared to Thick Film Resistors. They can achieve tighter resistance tolerances, typically ranging from 0.1% to 1%, whereas thick film resistors typically have tolerance values of 0.5% to 10%. Thin film resistors also provide a wider range of resistance values, including lower resistance values in the milliohm range.

6, Cost-Effective:
General purpose Thick Film Resistors are the most prolific part used in electronic and electrical devices today. As a result, they are the most widely available and lowest cost of any resistor technology. For general purpose applications that don’t require low TCR or tight tolerance, thick film ceramic resistors are generally the preferred solution.

7, Power Handling Capability:
Thick Film Ceramic Resistors have higher power handling capabilities compared to thin film resistors. The thicker resistive layer in thick film resistors allows them to dissipate more power without overheating. Thin film resistors, on the other hand, are more suitable for low-power applications.

It's important to consider these differences when selecting resistors for specific applications, as their unique properties can significantly impact circuit performance and cost.

Why Deed to Customize Thick Film Ceramic Resistors ?

Custom Thick Film Ceramic Resistors are specialized components designed to meet the specific requirements of certain electronic applications. Below are several reasons why Custom Thick Film Ceramic Resistors may be needed:

● Specific Tolerance Levels: Standard resistors may not offer the precision required for certain applications. Custom Thick Film Ceramic Resistors can be manufactured to have tighter tolerances, ensuring accuracy in circuit performance.

● Unique Power Ratings: Applications that require handling higher power levels may necessitate resistors with specific power ratings that are not available in standard offerings.

● Specialized Sizes and Shapes: For space-constrained environments or to fit into unique form factors, custom resistors can be designed with specific dimensions and shapes to fit the application perfectly.

● Material Requirements: Different applications might require resistors made from specific materials to withstand certain environmental conditions, such as high temperatures, corrosive environments, or to meet specific electrical properties.

● High Reliability and Consistency: Custom-made resistors can be manufactured to ensure high reliability and consistency in performance, which is critical for applications where failure is not an option.

● Long-term Availability: Custom Thick Film Ceramic Resistors can be produced in a way that ensures their long-term availability, even if standard equivalents are phased out or become obsolete.

● Regulatory Compliance: Custom Thick Film Ceramic Resistors can be designed to meet specific regulatory standards or industry certifications that are required for certain markets or applications.

● Cost Optimization: While initially more expensive, Custom Thick Film Ceramic Resistors can lead to cost savings in the long run by reducing waste, improving efficiency, and ensuring the longevity of the product.

● Innovative Applications: New and innovative electronic designs may require resistors with unique characteristics that cannot be found in standard products.

● Technical Support and Collaboration: Working with a manufacturer to create custom resistors often involves a collaborative process that can lead to better understanding and optimization of the final product.

Custom Thick Film Ceramic Resistors are chosen when the specifications of off-the-shelf components do not align with the specialized needs of a project, and when the performance, reliability, and longevity of the resistor are paramount.

Why Choose PANDA PCB For Thick Film Ceramic Resistors ?

● PANDA PCB Group specializes in delivering application-specific solutions for thick film ceramic resistors. We are experts in designing and manufacturing thick film power resistors, non-inductive ceramic resistors, high voltage resistors, radio frequency ceramic resistors, resistor networks, tubular ceramic resistors, and heater resistors. Our goal is to provide the best thick film resistor solutions for any given application.

● With over 20 years of engineering and manufacturing experience in thick film resistor products, Panda PCB understands that there are situations where compromises cannot be made to accommodate a standard thick film resistor. Especially in extreme environments or when reliability constraints exceed the capabilities of existing resistor components, a custom thick film resistor becomes the only viable option.

● Panda PCB has extensive experience in designing and manufacturing custom thick film resistors. We cater to low to medium volume production and provide support for both new designs and legacy projects. Additionally, we offer reverse engineering services to create replacements that fit obsolete devices for our customers' convenience.

Capabilities of Thick Film Ceramic Resistors Are As Follows :

Substrates :

Alumina (Al2O3)

Aluminum Nitride (AlN)

Beryllium Oxide (BeO)

Zirconium Dioxide (ZrO2)

Max Application Temperature :

662 - 1832

1832

2300

2432

Max Power Density (W/in²):

75

1010

250

300

Max Ramp Up Speed (°F/sec):

122

572

400

350

Thermal Conductivity (W/mK):

20-35

180-220

200-300

2.0-5.0

Density (g/cm³):

3.75

3.26

2.8

5.9

Dielectric Loss:

0.0001 - 0.001

0.0001 - 0.0005

0.0001 - 0.0002

0.0005 - 0.001

Dielectric Constant:

9.4 - 10.2

8.5 - 9.0

6.0 - 7.0

25 - 30

CTE, ppm/ºC:

6.0 - 8.0

4.0 - 5.0

7.0 - 9.0

10.0 - 11.0

Substrate Thickness (mm):

0.25 - 2.0

0.25 - 2.0

0.25 - 2.0

0.25 - 2.0

Typical Max. Dimension (inch):

6 x 12

5 x 11

6 x 6

4 x 4

Theoretical Total Wattage (W):

5400

55000

15000

20000

Paste ( Materials) :

Conductor Width/Space

Soldering / Bonding

Gold :

8/8mil (0.20/0.20mm)

Gold is a good conductor material and allows thermo-compression gold wire bonding and eutectic die attachment. It is, of course, costly and has poor solderability.

Silver :

8/8mil (0.20/0.20mm)

Soldering & Silver is lower in cost, and solderable, but is not leach-resistant with tin/lead solders.More seriously, silver atoms migrate under the influence of DC electric fields, both causing short-circuits and reacting with many of the resistor paste formulations.

Platinum-Silver :

6/6mil (0.15/0.15mm)

Soldering & Surface Mount, Palladium and platinum alloyed to the gold and silver produce good conductor pastes,with good adhesion to the substrate, good solderability, and moderately good wire bonding characteristics.. Copper and nickel are examples of materials that have been proposed for paste systems as substitutes for noble metals.

Palladium-Silver :

8/8mil (0.20/0.20mm)

Soldering & Surface Mount ,Solderable, Wire bondable, (good aged adhesion general purpose), Silver-palladium conductor inks are the most commonly used materials, with both price and performance (primarily resistance to solder) increasing with palladium content.

Platinum-Gold :

6/6mil (0.15/0.15mm)

Soldering & Au or Al Wire Bonding, Solderable (excellent aged adhesion with no migration).

Palladium-Gold :

8/8mil (0.20/0.20mm)

Soldering & Au or Al Wire Bonding, Wire bondable.

Performances :

Common Values/Range

Description

Resistance Value :

1Ω to several MΩ

The resistance value depends on the type and ratio of carbon black, typically ranging from 1Ω to Mega ohm.

Resistance Tolerance :

±1% to ±10%

High-precision resistors can achieve ±0.1% tolerance used laser trimming process.

Temperature Coefficient (TCR) :

±50ppm/°C to ±200ppm/°C

High-quality resistive paste should have a low TCR, preferably below ±100ppm/°C.

Stability :

≤1%

Resistors must undergo high-temperature aging and humidity tests to ensure stability.

Sintering Temperature :

850°C to 950°C

The sintering temperature for carbon paste depends on material properties, typically in this range.

Conductivity :

10⁶ S/m to 10⁸ S/m

Conductivity depends on the type and ratio of carbon black, affecting resistance precision and stability.

Surface Smoothness :

Ra≤ 1 μm

The surface must be free of cracks, bubbles, and non-uniform layers to ensure good mechanical and electrical properties.

Insulation Resistance :

≥10⁹ Ω

Carbon paste should have good insulation properties to avoid leakage or short circuits.

Mechanical Strength :

≥100 MPa

The resistive layer must have good compressive and bending strength to ensure the reliability of the resistor.

Volatility :

Solvent residue ≤ 1%

High volatility solvents help with even coating and drying, but excessive volatility may affect electrical performance.

Oxidation Resistance :

>1000 hours

High-quality carbon paste should have strong oxidation resistance to extend the service life.

Humidity Resistance :

≥1000 hours

Resistors should be able to withstand high-humidity conditions to ensure long-term stable performance, no significant changes.

1, Commonly used non-metallic materials for protective coatings include overglazes (Glass-Glaze), enamel, polymers, and epoxies,depending on application conditions and environment.

2, The insulating-protective layer for custom thick film ceramic resistor or heating element are all printed or coated continuously to cover the heater assembly as the sheath of the heating element with several intents: mechanically protecting physical damage, electrically insulating the heating traces, preventing corrosion along with water resistance, and thermally withstanding maximum application temperatures.